White-enameled steel vessel



UNITED STATES PATENT OFFICE,

SIMON RIESER, F MIDDLETOWN, CONNECTICUT, ASSIGNOR TO THE NEW ENGLANDENAMELING (30., A CORPORATION OF CONNECTICUT.

WHITE-ENAMELED STEEL VESSEL.

No Drawing. Original application filed November 21, 1916, Serial No.132,562. Di

cation filed July 16, 1919. Serial No. 311,377.

To all whom it may concern: Be it known that I, SIMON RIESER, a citizenof the United States, and a resident of Middletown, in the county ofMiddlesex and State of Connecticut, have invented a new and usefulImprovement in lVhite-Enameled Steel Vessels, of which the following isa specification.

My invention relates to white enameled steel vessels. Its object is toproduce such vessels with a single white enamel coat applied directly onthe steel.

It consists in the novel products hereinafter set forth.

Although many attempts have been made to produce a single white enamelcoat on steel, it has heretofore been found impossible to do so on apractical commercial scale or to produce a single white enamel coat onsteel that would be durable or that would be and remain free frommottling or staining. Whenever a single enamel coat has been applieddirectly to the steel, it has been found impossible, either to produce acolor sufliciently light, or to prevent the lightening properties of thematerials used being lost or destroyed in the process of manufacture, orto prevent such white enamel coat from mottling or staining, or to makesuch white enamel coat durable or possessed of sufficient stickingproperties to remain intact upon the steel in practical use. Either thebatch or mix has not been such as to permit the finished single coat tobecome white or to remain White, or the light color obtained during theprocess of manufacture has been destroyed, or the enamel coat has notpossessed sufficient sticking properties, or appears as a mottled orstained coat, or becomes so after bein produced, or will finish as arough, pitte face.

I have succeeded in overcoming all these difficulties and in producing awhite enameled steel vessel having a single white enamel coat applieddirectly on the steel, which coat not only has the necessary stickingqualities, but appears and remains white without mottling and staining,and is durable in practical use. It is as durable and useful, andpresents as white a surface, as white enameled steel surfaces which haveSpecification of Letters Patent.

Patented Nov. 30, 1920.

vided-and this app11- heretofore been produced by using more than onecoat, and its manufacture is less complicated and much cheaper.

I will now roceed to explain the preferred process y which I produce myimproved product, although it will be understood, of course, that manyvariations may be made in the materials used, in their proportions, andin the specific steps taken, wlthout departing from my invention.

Referring now specifically to the process which I prefer to follow inmaking my improved product, I first make a batch or mix that will, whensmelted, ground and mixed with the White-color-giving constituents,permit such constituents to impart a white color to the finished enamelcoat. This I obtain by using the materials hereinafter set forth for themix, or their equivalents.

I have found in practice that the followlng materials, with theproportions stated for each, give satisfactory results when used as abatch or mix, namely Borax 270 lbs. Feldspar 336 lbs. Quartz 120 lbs.Soda ash 90 lbs. Fluorspar 26' lbs. Bone ash 4.0 lbs. Refined sodiumnitrate 30 lbs.

White antimony, S13 0, oxid of antimony, Sb 4 52 lbs. Ammonium carbonate8 lbs. Black oxid of cobalt, C0 0 41oz.

Some of the above ingredients are used in making the batch or mixcommonly employed for the ground or grip coat upon which a white coat orcoats are superimppsed to form White enameled steel vessels.

y improved mix differs in ingredients and proportions from theingredients and proportions of such a ground or grip coat in omittingcertain materials that tend to darken, such as oxid of manganese andneedle antimony, in using white antimony $10 0, or oxid of antimony, SbO,,, in using a smaller proportion or amount of fluorspar, and,generally, in using a larger amount or proportion of materials that tendto lighten as distinguished from those that tend to darken, and also inomitting cry lite, commonly employed. in a superimposed 'whitecoat or ina white coat superimposed imparts suitable sticking properties to thefinished enamel, and will not prevent the white-color-givingconstituents, hereinafter referred to, from imparting a permanent whitecolor to thesingle enameling coat.

The batch or mix thus made is smelted in the usual way to form a frit.The frit is then ground in the mill with the usual amounts of water andclay, suitable for the purpose, added thereto, and is ground to theproper consistenc the same as in the ordinary treatment or preparing adip. The quantities of water and clay that I prefer to use are :-Ofwater, 33% per cent. of the weight of the frit; of clay, 6 per cent.

' of the weight of the frit. The ground mix ture thus obtained'would, inthe ordinary process of enameling upon steel, be called and treated asthe mill contents. In my preferred process, however, I preferably re-'move a portion of the soluble enameling constituents, such as solubleborates, silicates and the like, by allowing the mixture to stand untilthe heavier constituents have settled, and then I dip off the overlyinglayer of water with its soluble contents. The remainder, in my process,constitutes the mill contents. Any other suitable way may be used forobtaining in the mill contents the less amount of soluble constituentsabove described, such, for instance, as by put ting into the batchoriginally less amounts of such constituents.

I then mix a suitable proportion of the .mill contents withwhite-color-giving constituents, in such proportions as to impart to themixture a white color when properly set up and applied as a singleenameling coat to steel, without grinding the constituents of themixture any more than is enough to mix them sufliciently, so as topreserve the coarseness of the white-colorgiving constituents, toconserve their whitecolor-giving capacity or to revent .the grinding outof their color. preferably accomplish this by using in the mill arelatively small number of pebbles compared to those ordinarly used inenameling processes,

and I grind the mixture in the mill a relatively short time. Thus, asufiicient mixture of the various constituents is obtained,

while preserving the coarseness of the whitecolor-giving constituents.

Any suitable white-color-giving COHStIt".

uents may be employed, but 7 prefer to use as such a mixture'composed ofsodium antimoniate, tin oxid, and antimony sulfate,

i or their equivalents, in suitable proportions.

I find, in practical use, that the following proportions ofthese varioussubstances give satisfactory results, namely:To mix with 500 poundsofthe mill contents, 117% ounces .of sodium antimoniate; 27% ounces oftin i the mill contents.

I have found that, if the mixture of the mill contents and thewhite-color-giving constituents is ground too thoroughly or too long, ittends to destroy their white-colorgiving properties when applied as asin le white enameling coat to steel. Thus, if t e usual amount ofpebbles is used in the mill,

or if the grinding is kept up too long, the white color will disappearin the product.

I have found in practice that from about three-quarters of an hour toabout an hour in grinding, with one-half of the pebbles used in themill, gives satisfactory results.

After this grinding, the mixture is drawn from the mill and allowed tocool. It will cool in from three to six hours, although I prefer toallow from six hours to a day. The mixture thus produced I will, forsake of convenience, refer to hereafter as thev enameling mixture.

This enameling mixture is then ready to be set up.

I next prepare a setting up mixture by dissolving ammonium carbonate, orits equivalent, in water, in suitable proportions, and mix this settingup solution, preferably while hot, with the enameling mixture preparedas above described, mixing in suitable proportions with the enamelingmixture, and stirring the two until the proper consistency is obtained.The object of using ammonium carbonate is to set up the enamelingmixture without producing mottling in the finished enamel, and anymaterial that will do this is an equivalent for the carbonate ofammonia.

The ammonium carbonate may be dissolved in water in any suitable way,but I preferably do this by boiling it until the ammonium carbonate isdissolved. I have found that equal weights of ammonium carbonate andwater will give satisfactory results. The setting up mixture and theenamelin mixture may be combined in any suitable proportions. I havefound that 8 ounds of the setting up mixture when mixe with the amountof enameling mixture produced as above described will give satisfactoryresults.

The mixture should be stirred actively until the desired consistency isobtained. In practice, I prefer to continue this stirring until aheavier or thicker consistency is obtained than is usually employed inthe dip, for I have found that better results are obtained by dilutingsuch a heavier consistency with water as required When the dip ping ofthe steel vessel into the mixture is performed.

I have found that the use of the setting up mixture above describedtends to prevent mottling or staining of the single White enamel coatwhen applied directly to steel. It does this, as I understand it,because it i does not produce a strong salt, such as nitlates, chlorids,sulfates, etc., all of which tend to produce mottling.

The various steps of my process, the constituents used, and theirproportions may, of course, be Widely varied.

By my improvement, a durable, practical white enameled surface can beproduced on steel by the application of a single coat directly to thesteel. The surface presents as good an appearance as that of a Whiteenam' eled surface that has received tWo or more coats, and is as freefrom mottling or staining.

The ordinary operations of cleaning, pickling, Washing and drying of thevessels or surfaces to be enameled must be carried out With particularcare, to insure complete freedom from dirt of all kinds and also fromtraces of acid.

In the above-described preferred method of carrying out my process, Ihave referred to the mixing of the mill contents With thewhite-color-g1ving constituents as being done in a mill and by grinding.It is not essential that this mixing be done in this manner. Anysuitable Way or means for mixing the mill contents and theWhitecolor-giving constituents may be employed, and it is not essentialfor this purpose to use a mill, or even to grind the two together,although that is my preferred Way.

The present application is a divisional application of my applicationSerial No. 132,562, filed November 21, 1916, for process for producing asingle White enamel coat on steel and the product resulting therefrom.

What I claim as new and desire to secure by Letters Patent is As anarticle of manufacture, an unmottled White enameled steel vessel orsurface provided With a single White enamel coat placed directly uponthe steel.

In testimony whereof I have signed my name to this specification.

SIMON RIESER.

